car wont start on 1990 BMW 750iL

this v12 has 85,000 mi and sat for a couple years it did run out of gas once and just had the battery changed. when it cranks it sound like it jumped time. do these engines go through timing belts/chains this quickly?

1 answer
that's not the problem most likely its the fuel pump, if you don't run Super fuel the pump will gum up if it sits for a long time. i cant tell you how to fix it if you still need to.